Gas turbine engine used to power helicopters normally have a built in fuel schedule which is based on the operation at sea level and at a temperature of 59.degree. F. U.S. Pat. Nos. 3,587,229 and 3,777,478 typical fuel control systems for such gas turbine engines. U.S. Pat. No. 5,072,578 discloses an improvement for such fuel control systems to provide for a correction for temperature and altitude. This system operates in a satisfactory manner, however, it has been determined under certain conditions a collective pull on an input member by an operator may result in droop, a torque spike or rotor torsional vibration.